LXR linux/fs/proc/loadavg.c

   1#include <linux/fs.h>
   2#include <linux/init.h>
   3#include <linux/pid_namespace.h>
   4#include <linux/proc_fs.h>
   5#include <linux/sched.h>
   6#include <linux/seq_file.h>
   7#include <linux/seqlock.h>
   8#include <linux/time.h>
   9
  10#define LOAD_INT(x) ((x) >> FSHIFT)
  11#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
  12
  13static int loadavg_proc_show(struct seq_file *m, void *v)
  14{
  15        int a, b, c;
  16        unsigned long seq;
  17
  18        do {
  19                seq = read_seqbegin(&xtime_lock);
  20                a = avenrun[0] + (FIXED_1/200);
  21                b = avenrun[1] + (FIXED_1/200);
  22                c = avenrun[2] + (FIXED_1/200);
  23        } while (read_seqretry(&xtime_lock, seq));
  24
  25        seq_printf(m, "%d.%02d %d.%02d %d.%02d %ld/%d %d\n",
  26                LOAD_INT(a), LOAD_FRAC(a),
  27                LOAD_INT(b), LOAD_FRAC(b),
  28                LOAD_INT(c), LOAD_FRAC(c),
  29                nr_running(), nr_threads,
  30                task_active_pid_ns(current)->last_pid);
  31        return 0;
  32}
  33
  34static int loadavg_proc_open(struct inode *inode, struct file *file)
  35{
  36        return single_open(file, loadavg_proc_show, NULL);
  37}
  38
  39static const struct file_operations loadavg_proc_fops = {
  40        .open           = loadavg_proc_open,
  41        .read           = seq_read,
  42        .llseek         = seq_lseek,
  43        .release        = single_release,
  44};
  45
  46static int __init proc_loadavg_init(void)
  47{
  48        proc_create("loadavg", 0, NULL, &loadavg_proc_fops);
  49        return 0;
  50}
  51module_init(proc_loadavg_init);
  52